#include<iostream>
#include<cmath>
#include<cctype>
#include<string>

int main()
{
    using std::cin;
    using std::cout;
    std::string s;
    char ch;
    std::string s1,s2;
    const double PI=acos(-1);
    double a,b;
    double result;
    cout<<"please enter x and y,\n"
            <<" Q to quit.\n";
    while(1)
    {
        cin>>s1>>s2;
        a=std::stod(s1,0);
        b=std::stod(s2,0);
        result=std::atan2(b,a)*180/PI;
        cout<<result<<'\n';
        cout<<"x 和 y反正切值"<<result<<'\n';
        cout<<"please enter x and y,\n"
            <<" Q to quit.\n";
    }
    cout<<"Bye\n";
}